[NETFILTER]: Add partial checksum validation helper

[linux-2.6-omap-h63xx.git] / net / ipv6 / netfilter.c

diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
index aed51bcc66b44d5df82bd05775d674333a9e09c0..8c6c5e71f2102775e8215cfb29d9c2845bb1d79a 100644 (file)
--- a/net/ipv6/netfilter.c
+++ b/net/ipv6/netfilter.c
@@ -121,16 +121,44 @@ __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
        }
        return csum;
 }
-
 EXPORT_SYMBOL(nf_ip6_checksum);
 
+static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
+                                      unsigned int dataoff, unsigned int len,
+                                      u_int8_t protocol)
+{
+       struct ipv6hdr *ip6h = ipv6_hdr(skb);
+       __wsum hsum;
+       __sum16 csum = 0;
+
+       switch (skb->ip_summed) {
+       case CHECKSUM_COMPLETE:
+               if (len == skb->len - dataoff)
+                       return nf_ip6_checksum(skb, hook, dataoff, protocol);
+               /* fall through */
+       case CHECKSUM_NONE:
+               hsum = skb_checksum(skb, 0, dataoff, 0);
+               skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
+                                                        &ip6h->daddr,
+                                                        skb->len - dataoff,
+                                                        protocol,
+                                                        csum_sub(0, hsum)));
+               skb->ip_summed = CHECKSUM_NONE;
+               csum = __skb_checksum_complete_head(skb, dataoff + len);
+               if (!csum)
+                       skb->ip_summed = CHECKSUM_UNNECESSARY;
+       }
+       return csum;
+};
+
 static const struct nf_afinfo nf_ip6_afinfo = {
-       .family         = AF_INET6,
-       .checksum       = nf_ip6_checksum,
-       .route          = nf_ip6_route,
-       .saveroute      = nf_ip6_saveroute,
-       .reroute        = nf_ip6_reroute,
-       .route_key_size = sizeof(struct ip6_rt_info),
+       .family                 = AF_INET6,
+       .checksum               = nf_ip6_checksum,
+       .checksum_partial       = nf_ip6_checksum_partial,
+       .route                  = nf_ip6_route,
+       .saveroute              = nf_ip6_saveroute,
+       .reroute                = nf_ip6_reroute,
+       .route_key_size         = sizeof(struct ip6_rt_info),
 };
 
 int __init ipv6_netfilter_init(void)